140 FLORIDA STATE GEOLOGICAL SURVEY. 
i 
their water “artesian water.” The first meaning of “artesian 
well” was, therefore, a flowing well; and of “artesian water,” 
water under sufficient pressure to cause it to flow. With the 
extension into other areas of the use of deep wells as a source of 
water supply, many instances were found in which the water, 
although under pressure and rising almost to the surface, would 
not flow. In some cases the water will flow in areas of low 
surface elevation, and yet fail to flow in a slightly elevated area 
nearby. Artesian water thus came to mean water under pressure, 
causing it to rise in a boring when tapped, regardless of whether 
or not the pressure was sufficient to cause the water to rise above 
the surface level, and hence to flow. In the same way, and for 
similar reasons, the term “artesian well” came to include not 
only flpwing wells, but also' wells in which the water rises when 
the water-bearing stratum is tapped, regardless of whether or 
not the rise is sufficient to cause a flow. Occasionally, in popular 
usage, the term “artesian well” has been applied to any deep bor¬ 
ing, and “artesian water” to water from such a well. In this 
report the term artesian is applied to water under pressure, and 
hence rising in a boring when tapped. The water may, or may 
not, rise to or above the surface. An “artesian well” is any well 
reaching to and tapping a stratum bearing such water; a “flowing 
well” is an “artesian well” that gives a surface flow. Artesian 
pressure is the pressure causing the water to rise in the boring 
when tapped. This is essentially the usage of these terms as 
adopted by the Division of Hydrology of the U. S. Geological 
Survey.* 
CONDITIONS NECESSARY TO OBTAIN ARTESIAN 
WATER. 
As essentials for artesian water, it is necessary to have (1) 
an adequate source of water, and (2) the proper structural condi¬ 
tions to retain the water under hydrostatic or artesian pressure. 
It will be convenient to discuss first the structural conditions. 
*Water Supply and Irrigation Paper, U. S. Geological Survey No. 160. 
